Purpose: To validate the Central Sensitization Inventory (CSI), the Pain Sensitivity
Questionnaire (PSQ), the Douleur Neuropathique 4 (DN4) questionnaire, the painDETECT
(PD-Q) questionnaire, the Self Administered Leeds Assessment of Neuropathic Symptoms and
Signs (S-LANSS) and the Fibromyalgia (FM) Survey Score (FSS) as subjective proxies for
detecting CS in cases of endometriosis.
Justificaiton: There has yet to be a direct comparison among these six questionnaires in
endometriosis. Further research is needed to explore the overlap and effectiveness of
these measures in the context of endometriosis and CS. Moreover, these six questionnaires
have not been validated with quantitative sensory testing (QST) in
endometriosis.Quantitative Sensory testing (QST) is an objective assessment tool for
measuring CS. It quantifies the dynamic, altered modulation of nociceptive signals and
allows for the objective testing of somatosensory function and central sensitization by
applying various stimuli (such as pressure, pinprick, temperature etc.) to different body
regions and recording pain thresholds (Rolke et al., 2006). Therefore, in this study, our
objective is to compare the six patient-reported questionnaires to each other, and
determine whether each questionnaire correlates with QST thresholds.
Primary Objective: Validate the CSI/PSQ/DN4/PD-Q/S-LANSS/FSS questionnaires as proxies
for detecting CS in cases of endometriosis.
Examine the correlation between each questionnaire's scores with each other and the
number of central sensitivity syndromes and other pelvic pain-related comorbidities
(CSS) in patients with endometriosis.
Examine the association between questionnaire scores and the baseline QST thresholds
in patients with endometriosis.
Secondary Objectives: Examine how the questionnaires and QST thresholds, correlate with
pain severities, quality-of-life measured using the Endometriosis Health Profile (EHP-30)
scores, demographic variables, as well as examination and surgical phenotyping of
endometriosis.
Hypothesis: Higher scores on the CSI/PSQ/DN4/PD-Q/S-LANSS/FSS questionnaires will be
associated with lower QST thresholds (as well as an increased number of CSS and other
pelvic pain-related conditions) indicating greater central sensitization) in people with
endometriosis
Research Design: This study is a cross-sectional correlational study, where all data
points will be collected from participants at one point in time. The data collection
process will include the collection of scores on six pain questionnaires (i.e.CSI, PSQ,
DN4, PD-Q, S-LANSS and FSS) and threshold data from QST. All participants will be asked
to complete the questionnaires. Depending on QST eligibility, determined during the
screening assessment, and informed consent, a subgroup of participants will be asked to
complete additional QST to obtain threshold data. The data analyses will focus on
examining the relationships between each questionnaire and, for participants undertaking
both the questionnaires and QST, the relationship between QST thresholds and each
questionnaire.
Independent variables: Scores from the following questionnaires:
CSI: CSI total score
PSQ: PSQ minor score (avg. of scores from items 3,6,7,10,11,12,14) and the PSQ total
score (avg. of scores from items 1,2,3,4,6,7,8,10,11,12,14,15,16)
DN4: DN4 total score (sum of scores from items 1-7)
PD-Q: PD-Q total score (sum of 7 sensory questions)
S-LANSS: SLANSS total score
FSS: FSS total score (WPI+ SS= SS) Main Outcome Variables: QST thresholds for
assessment of CS PPT: avg. of duplicated PPT (kPa) at each test site VDT: avg. of
VDT (Hz) at each test site MPT: avg. of duplicated MPT (NmN) at each test site MDT:
avg. pain intensity rating on a 0-100' numerical rating scale (NRS) at each site SR-
Fucntion: avg. pain intensity rating on a 0-100' numerical rating scale (NRS) at
each site WUR: avg. of 5 WUR measurements (NmN) CPT: avg. of duplicated CPT (℃) at
each test site CDT: avg of CDT (℃) at each test site HPT: avg. of duplicated HPT (℃)
at each test site WDT: avg. of WDT (℃) at each test site CPM: avg. cearly CPM-effect
and late CPM-effecthange in HPT (pain intensity on NRS)
Analysis of Data:All statistical analysis will be conducted using R or IBM SPSS,
statistical software that allows for advanced data analysis, modelling, and
visualization. For the primary analysis, we will conduct correlation analysis (Pearsons
or Spearman's correlation) to assess the correlation, strength and direction of the
associations between each questionnaire with each other and with other pelvic pain
comorbidities (CSS). We will also examine the correlation/association between scores on
each questionnaire and baseline QST thresholds. We will also determine lower QST
thresholds correlate with an increasing number of CSS. For our secondary analysis,
summary statistics, bivariate testing, T-tests, Mann-Whitney U test or Kruskal-Wallis
tests will be conducted to determine the association between questionnaires and QST
thresholds, and with various socioeconomic, demographic and anatomical phenotyping
factors (e.g., endometriosis Stage, anatomic subtypes, histological confirmation,
coexisting adenomyosis). We will also conduct correlation analysis to determine the
association between pain severities and scores on the EHP-30. Regression analyses may be
done with adjustments will be made for potential confounders (e.g. age, endometriosis
stage and hormone therapy). All findings will be considered statistically significant at
a threshold of p < 0.05.